Portable hydraulic power device



H. J. DANA.

PORTABLE HYDRAULIC POWER DEVICE. APPLICATION FILED Aue.22, 1919.

1,343, 1 1 7. Patented June 8, 1920.

I 3 SHEETS-SHEET I. 7 .m

l2 I Z w E I|I I III WITNESS. I INVENTOR.

5i 6% BY A TTORNEY.

H. J. DANA.

PORTABLE HYDRAUUC POWER DEVICE.

APPLICATION HLED AUG.22, 1919.

3 SHEETS-SHEET 2- m u w Patented Jam 8, 1920 lllu INVENTOR.

WITNESS:

A T TORNE Y.

H. J. DANA. PORTABLE ,H'YDRAULIC POWER DEVICE.

APPLICATION FILED AUG.22, 1919.

1 ,3%8, 1 1 7. Patentedi June 8 1920,

3 SHEETS-SHEET 3:

WITNESS: IN VEN TOR.

A TTORN E Y.

ATENT OFFICE.

HOMER J. DANA, OF PULLMAN, WASHINGTON.

PORTABLE HYDRAULIC POWER DEVICE. v

Specification of Letters Patent.

Patented wa 8, 19%.

Application filed August 22, 1919. Serial No. 319,180.

To all whom it may concern:

This invention relates toa reciprocatory.

hand operated hydraulic device designed for applying a pushing or a pulling force to an object, and is especially adaptable for splitting logs and stumps or riving spruce, which work requires a pushing or driving force.

The object of the invention is to simplify and improve the existing art by producing a hydraulic power devlce of this character constructed of few parts which cooperate in such a manner as to accomplish the purpose for which the device is constructed 2 in an easler and more positive manner than has heretofore been-accomplished.

Other objects and advantages will present themselves as the nature of the invention is better-understood, reference being had to the accompanying drawings, in which:

Figure 1 is an elevation, parts being in section of the improvement, illustrating the piston in its projected position.

Fig. 2 is a similar view but showing the piston in its retracted position.

F'g. 3 is a sectional 'view, substantially similar to Fig. 1, but illustrating a modification. I

Fig. 4; is a similar view but showing the piston in its retracted position.

Fig. 5 is a sectional view through the four-way valve.

Fig. 6 is a detail perspective view of the end of the piston rod provided with the cutting head.

As disclosed by the drawin s the improvement comprises a cylinder 1 aving therein a movable piston 2 provided with a piston rod 3, the latter projecting through a stuiiing box 4 in one endof the cylinder. The piston 3 has its outer end provided with a cutting head which is preferably V-shaped in plan and which is designated by the numeral 5. Attached to the cylinder 1 by means of an angle duct dis a compensating chamber 7 the duct communicating with the head of the cylinder opposite that provided with the stuffing box through which the piston rod 3 passes. The numeral 8 indicates a hydraulic force pump having pipes or ducts 9 and 10 connected therewith, the said pipes being controlled by ahand operated four-way Valve 11, the pipe 9 communicatin with the cylinder through the head 12 t ereof, and the pipe 10 likewise communicating with the cylinder through the head 13 thereof. Both the heads 12 and 13 are provided with relief'valves 14; and 15 respectively.

Referring now particularly to Fig. 1, it will be seen that the piston is in extended position, the pump having been. operated to fill thecylinder 1 with water, the pump and ducts being likewise filled with water and the compensating chamber? is filled with air at atmospheric pressure. 2 The force pump 8 is operated to pump \the water through the duct .9 from the rear end of the cylinder 1 into the frpnt end through 1 the duct or pipe 10, creating a pressure against the front side of the piston 52 which causes it tomove toward the rear end of the cylinder and to draw the piston rod 3 into the cylinder. Since no water is ejected from the system, when the piston 2 is fully retracted (see Fig. 2), thevolume of water which fills the rear of the c linder'as in Fig. 1 must be disposed of. owever, the volume in the front end of the cylinder with the piston retracted is partly filled by the volume of the piston rod 3 and for this reason there is a surplus of water equal to the volume ofthat part of the piston rod which is drawn into the cylinder and-this surplus is crowded into the compensating already filling it. The volume of the compensating chamber 7 is somewhat in excess of the volume of water "displaced by the piston rod so that when the piston 2 is retracted the compensating chamber contains air and water under pressure.

To reverse the machine the four-way valve 11 is turned from the piston shown in Fig.

1 to that shown in Fig. 2. The pump is,

. chamber 7 against the pressure of the air f be pumped into; the front end of the cylininflowing of water in reserve in the compensating chamberfif. @This inf-lowing is augmented by the compressed air which is confined in the compensating'chamber. If

the pumping is continued the piston will travel to the position shown in Fig. '1 again,

the rear of the cylinder will be filled with Water and the compensating chamber will containonl'yair l l The compression of the air in, compensating chamberris only an incident in the operation, of the machine and is} not designed to actasa restoring agent for the purpose of extending the-piston after .it has been re 15 tracted. Again referring toFig. 1, we will assume the piston rod 3 to; have its head 5 contacting with some form of resistance to the rearward movement, such as a stump which is to be pulled, Upon the operation of the pump, ,8 the water is pumped from the rear end of the cylinder anddischarged into the front, end, causing the piston2 to move rearwardly drawing with it the piston rodv 3. However, the water displaced by the V rearward movementlof the pistoncan not all der, because partof this volume is already 00- i 'cupied by thepiston rod 3, This excess of 1 water is therefore crowded into the compenthe air already filling it, However, in the sating chamber 7,+against the resistance of I front end of the cylinder there will be a solid volume ofwater exerting pressure against v the piston 2 and; this performs the work against the resistance, such as thelpulling of v the stump. V i L Againreferring to Fig. we :will assume 'thepiston rod to? engage someform of resistance' to its outward travel. This might be the resistance of alog to the insertion of a wedge. Y The pump, draws the water from the front-end and forces it into therear end of the cylinder and in so doing exerts a force 1 against the rear faceofthe piston 2.; There is. always an equal force exerted upon the compensating chamber Whlch fWill counteractthe ejecting force ofthe compressed airconfined within it. If the pump develops sufficient force inthe rear end of the cylinder the air in the compensation chamber will be further compressed, allowing a greatervolume of water to enter it, thus increasing the v the deficiency of the water in the cylinder; When this-continues the pump will.

tend to'create a vacuumin the front endof 1 the cylinder and ifcontinued long enough it a will succeed in: creating a vacuumand stop the action of the'pumpj entirely, as ahydraulicpump will not work against 1 a vacuum.

This is relieved by opening the relief valve 15 and admitting air to the front end of the cylinder which allowsi the water to run into the pump and allow the lattertoresume its normal operation untilnall of the Water is exhausted from the front end of the cylinder;

If the volume of the compensation chamber is but very little in excess of the volume of the piston rod then the piston can always be forced out to almost its fully extended position. Upon reversin the machine it can be-restored to normal by leaving the relief valve 15-open until all ofthe air that has previously been admittedhas been expelled by the inflowing water. This is accomplished by locating the relief valve15 close to the top ofthe cylinder,and by attaching the duct or pipe 10 down low so that its a mouth will be covered with the water as long as there. is "Water in that end of the cylinder. This is also true with respect to the location of the relief valve l l and'the mouth of the duct 9. 1

In the, pulling operation there is no air cushion in the working end of the cylinder, and for each stroke of the pump there must be a corresponding movement of the piston.

In the splitting operation there is an air cushion in the end of the cylinder performing thework and for most'uses to which the machine can be put, this air cushion is obthe cylinder in the same manner as illustrat-ed; in FigsQl and 2 of the drawings, the

said ducts being under the'control of a fourway valve 11 and being'also connected to the force pump 8-. When this machine is employed for pulling the valve 19 is closed and the valve 18 is opened, thus putting the compensation chamber and air cushion in connec- 'jectionable. Therefore, as illustrated inv tion with the rear end ofthe cylinder 1.

For the splitting operation the valve 18 is opened and the valve 19 is closed,'connecting the compensation chamber with the front end of the cylinder, and thus traversing the air cushion from the Working or pressure end to the opposite end of the'cylinder. The operation of'the machine with this connection is essentially the same as where the arrangement heretofore described is employed for pulling work The addition of the valves 18 and 19' and theduct 17 facilitates the adaption of the machine to operate most effectively either as'a splitter or as apuller, although either arrangement will perform both functions successfully if the necessary manipulation of the relief cocks is carried out, i

Having thusdescribed the invention, what is claimed as new, is

1. In aport ablehydraulic power device, a cylinder, a pistonjtherein and a piston rod therefor projecting through one end of a cylinder, a compensating chamber; a valved der, a compensating chamber arranged over duct connecting said chamber to the cylinthe cylinder, valved ducts connecting said der to the rear of the piston, a source of fluid chamber to the ends of the cylinder, a source supply, a pump therefor, ducts from said of-fluid supply, a pump therefor, ducts from 5 pump connected to the ends of the cylinder, said pump connected to the ends of the cylin- 15 a four-way valve controlling said ducts, and der, a four-Way valve controlling said ducts, relief valves in the ends of the cylinder. and relief valves in the ends of the cylinder.

2. In a portable hydraulic power device, a In testimony whereof I affix my signature. cylinder, a piston therein havin a piston 10 rod projecting through one end or the cylinv HOMER J. DANA. 

